1. Field of the Invention
The present invention relates to a construction of a side panel erected at both side edges of a truck platform.
2. Description of the Related Art
A truck platform side wall construction has conventionally been known in which a side wall erected at both side edges of a truck platform includes an outer panel constituting a side external wall of the platform and an inner panel constituting a side internal wall thereof, and each of the panels has a top portion, a depending portion that depends downward from the top portion on the inside of the platform, and an external wall portion extending downward from a vehicle outside end portion of the top portion (for example, refer to claim, Specification 3rd line to 18th line on page 9, FIG. 2, and FIG. 5 of Unexamined Japanese Utility Model Publication No. 63-110176). In this truck platform side wall construction, the top portion of inner panel is arranged under the top portion of outer panel, and the depending portion of outer panel and the depending portion of inner panel are lapped on each other in a state in which the depending portion of outer panel is positioned on the inside of platform, the lapped portions being spot welded. The top portion of inner panel is formed with a plurality of protrusions that project upward and are arranged in the longitudinal direction of platform, and these protrusions are brought into contact with the lower surface of outer panel top portion. A gap is formed between the top portions of both panels excluding the contact portions and between the external wall portions near the top portions, and a notch is formed in a portion adjacent to the protrusion in the depending portion of inner panel.
In the truck platform side wall construction configured as described above, when an external force acts on the platform from the rear side, stress is concentrated at the notch, and the side wall is deformed in this portion, by which the energy of the external force is absorbed. As a result, the platform is prevented from hitting a cab with a large force. Also, the deformation of cab can be prevented without a strong reinforcing member provided at the rear part of the cab, so that the manufacturing cost of cab can be reduced.
On the other hand, there has been disclosed a truck platform construction in which recesses are formed at predetermined intervals in the longitudinal direction of platform in inside projecting inclined surfaces of inner panels of the right and left side panels of platform; a rope hook of a U shape in plan view is fixed in the recess; and a stake insertion hole is formed in a top rail portion of side panel just above the rope hook (for example, refer to claim, Specification 15th line on page 3 to 5th line on page 4, and FIGS. 1 to 6 of Unexamined Japanese Utility Model Publication No. 3-43089).
In the truck platform construction configured as described above, the stake is inserted through the stake insertion hole formed in the top rail portion of side panel, and the lower end of stake is fitted in an inside space of rope hook in the recess, by which a stake deck can be formed. Also, by hooking a rope to the rope hook, a cargo can be fixed, which is the inherent object of the rope hook. Further, by placing a bridging material between the rope hooks in the recesses provided in the right and left side panels, cargoes can be stacked up in two tiers.
However, in the conventional truck platform side wall construction described in Unexamined Japanese Utility Model Publication No. 63-110176, the notch is formed only in the inner panel, and no notch is formed in the outer panel. Therefore, when an external force acts on the platform from the rear side, energy is not absorbed sufficiently in some cases.
Also, in the conventional truck platform side wall construction described in Unexamined Japanese Utility Model Publication No. 63-110176, when the inner panel is formed by a synthetic resin to improve the appearance of the inside of the platform, the lapped portion of the depending portion of outer panel and the depending portion of inner panel must be fixed to each other by using bolts and nuts in place of spot welding. In this case, since the shape of inner panel is intricate, the formability of inner panel is decreased, and also, as described above, when an external force acts on the platform from the rear side, energy is not absorbed sufficiently in some cases.
Further, in the conventional truck platform construction described in Unexamined Japanese Utility Model Publication No. 3-43089, the hole formed in the top rail portion of side panel is provided only to insert the stake for constructing the stake deck, and there is no technical concept that when an external force acts on the platform from the rear side, the energy thereof is absorbed. Since the hole is exposed in the top rail portion, there arises a problem in that the appearance of top rail portion is marred.